Out-breeding behaviour and xenophobia in the Damaraland mole-rat, Cryptomys damarensis

Abstract

Out-breeding behaviour and xenophobia were investigated in laboratory colonies of the Damaraland mole-rat, Cryptomys damarensis. Foreign males and/or females were introduced into reproductively quiescent colonies and colonies which were actively breeding. Although males attempted to mate with familiar or related females, females only mated with foreign males. This suggests that female avoidance of incest is responsible for outbreeding in this species. Resident males in reproductively quiescent colonies did not attack foreign males or females. However, resident males in actively breeding colonies attacked and kilted foreign males. Resident females in reproductively quiescent colonies attacked foreign females but attempted to mate with foreign males. However, in colonies in which the breeding female was approaching parturition, resident non-breeding females also attacked foreign males. Once foreign females attained reproductive status in the colony into which they were introduced they killed all the resident females. These results suggest that xenophobia in the Damaraland mole-rat is influenced by whether or not the colony is actively breeding, and by the reproductive state of the breeding female.